Piggeries set to become energy producers

THE West Australian pork industry is helping farmers reduce their carbon footprint by embracing the benefits of on-farm biogas energy.

Piggeries can reduce energy costs and support the environment by recycling manure using anaerobic digestion to produce renewable energy.

The organic waste from the piggeries is collected in covered ponds, which trap the natural gases that are created. The most popular biogas system uses unheated conventionally covered lagoons because they are cost effective and low maintenance.

Leader of CRC for High Integrity Australian Pork, Rob Wilson says anaerobic digestion technology enables microorganisms to decay the organic waste material in the absence of oxygen to create biogas.

“There is a particular bacteria that breaks down the material and the by-product of that are methane, carbon dioxide and some other gases. Normally they just emit into the air as greenhouse gases,” Dr Wilson says.

However, farmers are now able to use these gases to generate heat and electricity.

“The best way is to utilise the methane to produce energy. Biogas is a mixture of gases, mainly methane which can be captured and used to heat a hot water boiler,” he says.

Piggeries often need to heat the floors for their piglets and the biogas allows the farmers to do this while still looking after the environment. The biogas can be used for direct or combined heating and power. The excess energy can also be sold back into the grid.

“Some of that heating can be either electricity for hot water, you can replace your LPG with biogas and produce hot water, or you can run your biogas into a generator and produce electricity,” Dr Wilson says.

Biogas production in piggeries will help local farmers to save power costs and to reduce their greenhouse gas emissions. Dr Wilson says using on-farm biogas could see emissions drop by as much as 60-80 per cent.

Piggeries currently produce around 3-4kg of Co2 per kg of pork though Dr Wilson says this can be reduced with on-farm biogas energy.

“It’s possible to get that down to 1kg Co2 equivalent per kg of meat produced. That’s one big benefit.”